ISU

We have a long seat of width X centimeters. There are many people who wants to sit here. A person sitting on the seat will always occupy an interval of length Y centimeters.

We would like to seat as many people as possible, but they are all very shy, and there must be a gap of length at least Z centimeters between two people, and between the end of the seat and a person.

At most how many people can sit on the seat?

Constraints

• All input values are integers.
• 1 \leq X, Y, Z \leq 10^5
• Y+2Z \leq X

Input

Input is given from Standard Input in the following format:

X Y Z

Output

Print the answer.

Examples

Input

13 3 1

Output

3

Input

12 3 1

Output

2

Input

100000 1 1

Output

49999

Input

64146 123 456

Output

110

Input

64145 123 456

Output

109

inputFormat

input values are integers.

• 1 \leq X, Y, Z \leq 10^5
• Y+2Z \leq X

Input

Input is given from Standard Input in the following format:

X Y Z

outputFormat

Output

Print the answer.

Examples

Input

13 3 1

Output

3

Input

12 3 1

Output

2

Input

100000 1 1

Output

49999

Input

64146 123 456

Output

110

Input

64145 123 456

Output

109

样例

100000 1 1

49999